A. Field of the Invention
This invention relates to the field of cushioning devices, gelatinous elastomers and devices made therefrom. More particularly, some embodiments of this invention relate to a cushion or cushioning device made in whole or in part of gelatinous elastomer, gelatinous visco-elastomer, and the elastomers themselves, methods for making any of the foregoing, and structures made from the foregoing and other cushioning structures and other devices including gelatinous elastomers.
B. The Background Art
In the prior art, there have been numerous attempts to provide a cushion which achieves comfort by eliminating peak pressure areas and by evenly distributing the cushioning force over a broad surface area. Some of these attempts include foam cushions, fluid cushions, flowable heavy gel cushions, lubricated microsphere cushions, thermoplastic honeycomb film cushions, traditional spring mattressing, and gelatinous elastomers generally. Examples of prior art gelatinous elastomers include the patents of John Y. Chen of Applied Elastomerics, Inc. of Pacifica, Calif. Some of Mr. Chen""s patents include U.S. Pat. Nos. 5,884,639; 5,868,587; 5,760,117; 5,655,947; 5,633,286; 5,624,294; 5,508,334; 5,475,890; 5,336,708; 5,334,646; 5,324,222; 5,262,468; 5,239,723; 5,153,254; 4,618,213; and 4,369,284. Mr. Chen""s gel appears to be anticpated by two other prior art patents: U.S. Pat. No. 3,827,999 issued to Crossland and U.S. Pat. No. 5,618,882 issued to Hammond et al.
It is an object of some embodiments of the invention to provide a cushion that distributes supporting pressure on an object being cushioned in a manner that is generally even and without pressure peaks. It is a feature of some embodiments of the invention that the cushion has a low surface tension and permits a cushioned object to sink deeply into it. This action is due to compressibility of the cushion. It is also a feature of some embodiments of the invented cushion that some of the columns present in the invented cushion tend to buckle under the weight of the object being cushioned. This buckling is especially useful in accommodating protrusions from the object being cushioned into the cushion. The ability to accommodate protrusions through buckling of the cushion columns eliminates pressure peaks. It is a consequent advantage of the invention that the invented cushion is comfortable and does not tend to constrict blood flow in the tissue of a human being on the cushion, thus being suitable for medical applications and other applications where the object being cushioned may be immobile for long periods of time, such as in footwear, automobile seats, furniture, mattresses, and other applications.
It is an object of some embodiments of the invention to provide a cushion that eliminates the head pressure found in some fluid cushions. In fluid cushions, the flowable media may be drawn by gravity so that it exerts pressure on some portions of the cushioned object as the cushioning media attempts to flow in response to the gravitational force. This pressure is referred to as xe2x80x9chead pressure.xe2x80x9d Head pressure can cause discomfort and tissue damage to a human using the cushion. The preferred embodiments of the invention do not develop head pressure.
It is an object of some preferred embodiments of the invention to provide a gelatinous elastomer from which cushioning devices may be made. Some preferred embodiments of the invention provide such a gelatinous elastomer with distinct strength advantages, elongatability, and bleed reduction compared to prior art gelatinous elastomers.
These and other objects, features and advantages of the invention will become apparent to persons of ordinary skill in the art upon reading the specification in conjunction with the accompanying drawings.